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| Hitoshi Mukai | |
| Senior Researcher | |
| Global Warming Mechanism Research Team | |
| Global Environment Division | |
| National Institute for Environmental Studies, Ministry of Environment | |
| Onogawa 16-2, Tsukuba, Ibaraki, 305-0053, Japan | |
| Tel: +81-298-50-2536 Fax: +81-298-50-2569 | |
| E-mail: lnmukaih@nies.go.jp |
13,228,000 Yen
(FY 2000: 13,228,000 Yen)
Although high precision was required for the measurement of carbon isotope ratio of CO2 in the atmosphere, data provided by various labs was known to have systematic gaps with each other. To assimilate these data we have to study the cause of the gaps and develop methods for removing these gaps. In this study, one reference material for atmospheric CO2 isotope analysis was prepared to be distributed to the researchers in the world. The reference CO2 (NACIS) had isotope values similar to those of atmospheric CO2. In terms of homogeneity, NACIS could be a good reference to compare isotopic scale in each laboratory. Several cooperative analyses showed a good agreement in C isotope ratio with a range of 0.1 per mil. Systematic shift of the scale was considered to be related to cross contamination effects in Mass spectrometer. The cross contamination effect for the mass spectrometer in NIES was about 0.3% for C isotope analysis and 1.1% for O analysis, which gave a considerable shift on our scale compared to CSIRO in Australia. In November, a workshop was held to discuss such technical problem on isotope analysis and newly proposed inter-comparison plan for GHGs (GLOBALHUBS). The researchers from 8 countries gave their presentations far 2 days.
Carbon dioxide, Carbon isotope analysis, Oxygen isotope analysis, Cross contamination, 17O correction.